\\[-1.8ex] Soil Heterogeneity & $-$0.016 & $-$0.009 & $-$0.007 & $-$0.009 & $-$0.008 & $-$0.009 \\ 
  & (0.022) & (0.021) & (0.020) & (0.020) & (0.021) & (0.021) \\ 
  & & & & & & \\ 
\\[-1.8ex] 
Observations & 380,379 & 380,379 & 380,379 & 380,379 & 377,766 & 377,766 \\ 
R$^{2}$ & 0.035 & 0.035 & 0.036 & 0.036 & 0.037 & 0.040 \\ 
